Egg hatching of the maple aphid, Periphyllus californiensis Shinji, was observed on saplings of Acer amoenum Carriere in two microhabitats, i.e., the understory of a maple stand (a shaded site) and an open area in a nursery (a sunny site), over a 2-year period. Buds of A. amoenum opened earlier at the shaded site than at the sunny site and eggs of P. californiensis also hatched a little earlier...

In birds, the link between parental care behaviour and prolactin release during incubation persists after hatching in altricial birds, but has never been precisely studied during the whole rearing period in precocial species, such as ducks. The present study aims to understand how changes in parental care after hatching are related to circulating prolactin levels in mallard hens rearing ducklin...

Chicks initiate bilateral alternating steps several days before hatching and adaptively walk within hours of hatching, but emergence of precocious walking skills is not well understood. One of our aims was to determine whether interactions between environment and movement experience prior to hatching are instrumental in establishing precocious motor skills. However, physiological evidence of pr...

The viability of Ochlerotatus albifasciatus (Macquart) eggs stored at room temperature and at 5 degrees C was studied over 31 months. After 12, 18 and 31 months of storage, eggs were acclimatized at 22 degrees C for ten days, and then inundated twice every seven days. The effect of the storage period on the percentage of hatching was analyzed by one way ANOVA. Differences on the hatching respon...

objective: the aim of this study was to investigate the effect of laser assisted hatching on the development and quality of vitrified-warmed 4-cell stage mouse embryos. materials and methods: the vitrified-warmed 4-cell mouse embryos were divided into two groups: control group (without laser assisted hatching) and experiment group (with laser assisted hatching). all embryos in both groups were ...

abstract the various stages of embryonic growth pharaoh´s cuttlefish (sepia pharaonis) reside in oman until hatching was studied. gregor tours and the eggs collected for further study of the propagation of education, research center of the earth - chabahar moved .once every 24 hours to get detailed information was sampling of from fertilized eggs. egg size of 11±4 mm were selected because of th...

Accelerated hatching is one of few defences available to embryos, and is effective against many egg-stage risks. We present the first analysis of genetic variation in hatching plasticity, examining premature hatching of American toad embryos in response to pathogenic water moulds. We reared eggs from half- and full-sib families in the presence and absence of water mould. Hatching age and hatchl...

Meloidogyne incognita egg masses were immersed in different concentrations of six volaule fatty acids to bioassay their toxic effect on embryonic development and hatching. Exposure to a 250 ppm aqueous solution of volatile fatty, acids completely suppressed egg hatching within 48 hours. When exposed to a 125 ppm concentration hatching was reduced 75 % by acetic acid, 91% by propionic acid, 23% ...

considering the crucial importance of daphnia species in aquaculture, in particular for artificially- cultured sturgeon fry, a comprehensive study on the hatching requirements of their diapausing eggs seemed to be inevitable in order to obtain the ideal hatching technique. to do so, the ephippial eggs were collected from live food ponds in the cultivation and breeding centre of gorgan and after...

Adult crickets (Gryllus bimaculatus) were maintained under a 12-h light:12-h dark cycle (LD 12:12). After oviposition, their eggs were incubated under different lighting regimens at 23 degrees C, and temporal profiles of egg hatching were examined. When the eggs were incubated in LD 12:12 or in DL 12:12 with a phase difference of 12h from LD 12:12, throughout embryogenesis, 88% to 97% of hatchi...